Hi Tony;
Just a few 'Sunset'-isms from memory.
In an oversimplification, the flying of the mansion was akin to the world's largest flying drawer slides with the mansion itself forming the drawer.
There were something like 5 or 6 pairs of hard legs.
Three of the legs on each side, all of the odd or even numbers, I can't recall which, had full height 'I' beams on their on-stage edges.
These 6 vertical 'I' beams began in the basement, ran up through the stage, through the touring deck, through the theatre's own grid and on upwards to create two additional custom grids above the original grid.
The tops of the 6 'I' beams were tied side to side and U/S - D/S between each other and on out to the side and U/S and D/S walls for horizontal stability.
Standard flown items were on the original grid.
Heavier pieces, like the pool surround and our 'On The Road' piece were one level above the normal grid.
The mansion was supported from the top-most level, I suppose primarily to provide clearance for the rigging and the diagonally routed support cables.
On top of each of the six vertical columns was a massive sheave on the order of 24" to 30" in diameter and grooved for a single 1.125" cable. Could've been a 1.25" cable, don't whip me, it was a while back.
Across the centre of the U/S wall were two massive beams supporting six more sheaves serving as headblocks for the counter-weights.
In plan view, these six sheaves were angled towards their respective column sheaves which were, of course, angled towards their headblocks.
This meant that the six supporting cables ran diagonally across above the uppermost grid from the columns to the headblocks.
On either side of the stage, supported by 3 cables each and captured to the vertical columns by a myriad of casters, was a huge mothering horizontal 'I' beam running U/S - D/S.
These two beams formed the flying portion of the 'drawer slides'.
The mansion formed the drawer.
Opening and closing the 'drawer' allowed the mansion to track U/S - D/S whether in the air or, seemingly, on the deck.
Flying the 'drawer slides' flew the mansion.
The mansion was pretty massive, not only in weight but in height, width and U/S - D/S depth as well.
When the mansion was flown U/S and out to it's high trim, it occupied so much of the stage tower that it contained elements of several LX pipes underneath it within it's raked floor.
Rigging was by the fine lads from Feller Precision.
The mansion flew with the motivation of a redundant pair of hydraulic motors driving either end of a common drive shaft through a matching pair of planetary gearsets.
The drive shaft was USC essentially serving as the 'idler block' for the mansion's counter-weights.
The 'line lock', as it were, was a single disc brake in the neighbourhood of 3' in diameter near the centre of the 'idler shaft' with a redundant pair of hydraulically actuated calipers.
Since you saw the show, you know the mansion flew in and out complete with cast and crew on board.
The 1st National U.S. touring mansion was a pretty good trick too but nowhere near the scale of the permanent rigs.
Sorry to have droned on and, again, thanks for the memories!
Toodleoo!
Ron Hebbard